Process for cleavage of 7-amino-adipoylamino side chain in cephalosporins

摘要

A process is provided for preparing an ester of 7-amino-7-methoxy-3-acetoxymethyl or methyl-2- or 3-cephem-4-carboxylic acid by reaction of an imino halide <IMAGE> 1 wherein R'' is a carboxyl blocking group, and R3 is an amino protecting group, X is halo, preferably bromo or chloro, and A is hydrogen or acetoxy with the following cuprous methyl complex: